thesassyindian
Supporting Member
My tank is at 9.5dKH, and my new salt mix is 11.5dKH
Is it safe to do a 50% water change?
Is it safe to do a 50% water change?
Water change and Alkalinity
- Thread starter thesassyindian
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NanoCrazed
Guest
But you don't keep sps. So alk doesn't matter a great deal with softies. I've never cared about alk or ca much until getting into sps. And only control it on one of my 14 tanks...
max_nano
Supporting Member
It can be helpful for threads like this to link your journal so people can get a better idea of your system.
if you’re worried about an alk spike you can do smaller % WC. I have been doing small ones for my 25 gal tank, just 2-3 gal for this reason. But I do it small so I don’t have to worry about it, I dont test the newly mixed water but expect it to be in a 1+- range of the advertised 7dkh of the salt mix.
if you’re worried about an alk spike you can do smaller % WC. I have been doing small ones for my 25 gal tank, just 2-3 gal for this reason. But I do it small so I don’t have to worry about it, I dont test the newly mixed water but expect it to be in a 1+- range of the advertised 7dkh of the salt mix.
Coral reefer
Past President
Yeah just post this in your journal rather than making a new thread
You should probably be fine. I manually dose once a day to bring my tank up from 7.8-ish dkh to 9 dkh over the span of 5 minutes or so. (I would not necessarily recommend doing this, I have just been lazy about setting up my dosing pump and this has worked well for me for three months now.)
Popular wisdom holds to alter dkh by no more than 0.5 or 1 dkh/day (depending on your source), but Red Sea suggests no more than 1.4 dkh in a 24 hour period.
You're still towards the low end of the recommended range (8-12 dkh) so it should be fine. Any higher and I'd be a bit concerned, since Alkalinity acts like a buffer, and buffers aren't linear in their buffering capacity. They buffer real well... Until they suddenly don't, and pH/calcium/etc can go out of whack very quickly.
Popular wisdom holds to alter dkh by no more than 0.5 or 1 dkh/day (depending on your source), but Red Sea suggests no more than 1.4 dkh in a 24 hour period.
You're still towards the low end of the recommended range (8-12 dkh) so it should be fine. Any higher and I'd be a bit concerned, since Alkalinity acts like a buffer, and buffers aren't linear in their buffering capacity. They buffer real well... Until they suddenly don't, and pH/calcium/etc can go out of whack very quickly.
Regarding those alkalinity ranges, it’s worth pointing out that natural reefs in the ocean are around 7 dKh, and that some of the more controlled systems out there recommend aiming for 7 or 8. There are lots of reports of people causing a ton of coral damage by pushing the dKH up into the 10+ range and having the slightest perturbation come along and cause a crash. You can find the 8-12 range referenced lots of places online, but I don’t agree with it, I think it’s somewhat outdated and risky advice. I keep mine around 8.5.
thesassyindian
Supporting Member
+ @max_nano
Just did! Thanks for the suggestion!
Thesassyindian's 13.5 gallon m̶o̶n̶e̶y̶ ̶p̶i̶t̶ nano mixed reef
Hello folks, I am new to BAR and the reefing hobby. In fact, this is my first foray into pet keeping, period. Thank you @IOnceWasLegend for introducing me to BAR. This group has been a great resource since day one. I have been contemplating the hobby for the last 2-3 years, and been reading...
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For what it's worth, I agree with that sentiment and I think that the decreased buffering capacity is likely the cause of crash in ranges that high. I was surprised to see that natural seawater was only 7 dkh after learning about alkalinity, given the 8-12 dkh range. Temporarily I think it's okay, but I wouldn't want to chance it by keeping my system at a high range (I keep mine at ~8.5-9, but that's because everything is happy and I like the, "If it ain't broke, don't fix it" approach).